Our Organic Mushrooms blend is superior to any other mushroom supplement for dogs and cats and is certified to be the highest quality available in the world. We use 10 USDA organic mushrooms from 100% fruiting bodies containing the highest levels of Beta glucansthe active polysaccharides that support healthy immune function. We then combine them to create the ultimate immunity blend from the most effective mushrooms found in nature. Fera Pet Organics uses real mushrooms, organically cultivated and naturally grown, free from heavy metals and agricultural chemicals, certified organic and Kosher. Our mushroom blend is superior to any other mushroom supplement for dogs and cats and certified to be the highest quality available in the world. We only use organic mushrooms (100% fruiting bodies) with high levels of beta-d-glucan. No mycelium, no grain, no starch.